Breadth First Search
In plain terms
Exploring a graph level by level outward from a start node.
Going deeper
BFS visits all neighbors at the current distance before moving farther, using a queue. It finds the shortest path in unweighted graphs.
Under the hood
O(V+E) time; guarantees shortest paths in unweighted graphs and explores in expanding 'rings'.
Examples
Shortest path (unweighted), web crawling, social-network degrees, maze solving.
Think of it like...
Like ripples spreading out from a stone dropped in water, reaching nearest points first.